An emergency medical device (e.g., an external defibrillator/monitor) is used in emergency lifesaving situations where seconds count. For example, when someone succumbs to a sudden cardiac arrest, the likelihood of resuscitation decreases each minute thereafter. Thus, it is critically important for the emergency medical device to be ready for use when it is needed. Consequently, device readiness indicators are commonly used in emergency medical devices to inform the user whether or not the emergency medical device is ready-for-use.
In practice, many emergency medical devices are turned-off most of the time and standard protocol mandates a periodic assessment of whether the emergency medical device is ready-for-use. To this end, an emergency medical device typically performs automatic self-tests on an hourly or daily basis when the emergency medical device is turned off, but has power available to conduct the self-tests. The device readiness indicator provides visual and/or auditory signals informative of either a pass result or a fail result of the self-tests. For example, the device readiness indicator may be displayed as a green check mark icon to indicate a ready-for-use pass result or as a red X mark to indicate a not-ready-for-use failed result.
A limitation of this scheme is that there is no advanced warning of a pending failure of a ready-for-use emergency medical device. Specifically, the device readiness indicator will indicate the emergency medical device is ready-for-use until self-tests indicate the emergency medical device is no longer ready-for-use. Working with only this Boolean indicator, designers of emergency medical devices are constrained to characterize marginal test results as failures, with the possible implication of a false failure that needlessly takes a properly functioning emergency medical device out of service. A further consequence of this Boolean indicator is that a subsystem monitoring of the emergency medical device fails to detect condition(s) that indicate the emergency medical device is likely to operationally fail in the near future.
More particularly, referring to FIG. 1, an illustrated operational readiness assessment state diagram consists of a self-testing/analysis state S10, a subsystem monitoring state S11, an error analysis state S12 and a service/repair state S13 for assessing the operational readiness of the emergency medical device.
Self-testing/analysis state S10 involves an execution of various self-testing by the emergency medical device of each subsystem of the emergency medical device. As will be further explained subsequently herein, a subsystem of the emergency medical device employs operational components for executing an emergency medical procedure including, but not limited to, an electrocardiogram monitoring procedure, a defibrillation shock therapy procedure, a synchronized cardioversion therapy procedure and a transcutaneous pacing therapy procedure. The self-testing of such operational components involves a delineation of a hard functional limit between being deemed either operationally ready or inoperable for purposes of the associated emergency medical procedure.
If one or more of the subsystems fails self-test(s) executed by the emergency medical device, then the emergency medical device is triggered to transition T1 to service/repair state S13 whereby the emergency medical device indicates a service/repair is needed for the emergency medical device (e.g., a red X mark icon is activated).
Otherwise, if the subsystem(s) pass the self-tests executed by the emergency medical device, then the emergency medical device is triggered to transition T2 to subsystem monitoring state S11 whereby the emergency medical device indicates all subsystems are ready-for-use (“RFU”) (e.g., a green check mark icon is activated).
While waiting for use or actually in use during subsystem monitoring state S11, the emergency medical device will be triggered to transition T3 to error analysis state S12 when an error by a subsystem occurs that threatens the operational readiness of the emergency medical device. The error may be a recoverable error or non-recoverable error (i.e., a failure).
If the emergency medical device is able to recover from an error, then the emergency medical device is triggered to transition T4 back to subsystem monitoring state S11.
If the emergency medical device is unable to recover from an error but is reinitiated nonetheless by an operator or automatically, then emergency medical device is triggered to transition T5 to self-testing/analysis state S10.
If the emergency medical device has failed subsystem(s) without being reinitialized, then the emergency medical device is triggered to transition T6 to service/repair state S13.
In practice, the operational readiness assessment state diagram may be implemented in various modes, but regardless the subject state diagram fails to detect condition(s) that indicate a subsystem of the emergency medical device is likely to operationally fail in the near future.